Dhaka: A Bangladeshi court today sent three members of a banned Islamist group, who were arrested in connection with the brutal killing of a head priest of a Hindu temple, to 18-day police custody for their interrogation in the case, the latest incident of violence targeting religious minorities in the Muslim-majority country.

With the arrest of the three members of the outlawed Jamaat'ul Mujahideen Bangladesh (JMB), including the mastermind of the assault, during raids in Panchagarh and Nilphamari districts yesterday, police claimed to have completely solved the murder case.

"We have been able to completely crack the case," police's deputy inspector general for the region Humayun Kabir told media, adding that they directly carried out the murder of the priest.

The three JMB activists ? identified as Alamgir Hossain, 35, Harez Ali, 32 and Ramzan Ali, 22 ? were produced in a Panchagarh court under heavy security and were remanded in 18-day police custody for questioning.

So far, six persons have been arrested in connection with the killing. Three others who were arrested earlier were placed under 15-day custody for interrogation.

"No lawyer appeared at the court to defend the three," a journalist in Panchagargh told PTI as he was reached in Dhaka by phone.

The chief priest of Hindu temple Sri Sri Shantu Santo Gaurio, 50-year-old Jagneshwar Roy, was slaughtered on February 21 in Sonapota village, near the border with India, in a pre-dawn attack by the assailants who also injured two Hindu devotees before fleeing on a motorbike.

The Islamic State had claimed the brutal killing of the priest. However, police dismissed the claim and said that JMB operatives committed the murder.

The priest's murder was the first attack on a Hindu priest and the fifth assault on minority religious communities including Shia Muslims and liberal Sufi preachers in the past six months by suspected Islamists.

Hindus make the Sunni-majority country's largest minority with nearly 10 per cent of the total population of 160 million.